Whip stock



' o. B. TROTTER WHIP STOCK Feb. 14, 1939.

Fil ed June 29, 1957 FIG.2. FiG.3. FIG.4.

O B. TROTTER l ENTOR ATTORNEY Patented Feb. 14, 1939 UNITED STATES PATENT OFFlCE WHIP STOCK Odie B. Trotter, Houma, La., assignor to The Texas Company, New York, N.

tion of Delaware Y., a corpora- Application June 29, 1937, Serial No. 150,890

6 Claims.

.to a relatively small angle of deviation of the order of 2 or 3 degrees and this is due chiefly to the inflexibility of the drill rod which prevents the bit from following a whipstock having a taper greater than this amount. Another disadvantage of the usual type of whipstock is that it is not possible or practlcable'to withdraw the device from the hole after it has served its purpose and this, of course; adds materially to the cost of the drilling of wells, especially in those cases where it is necessary to use several whipstocks in succession in order to obtain the desired direction of the well.

In accordance with the invention, a flexible knuckle or ball and socket joint is inserted in the drill string between the bit and the collar, this joint permitting the drill bit to follow a whipstock having a taper asgreat as 5 degrees without unduly stressing the rods above the bit. A tubular extension is secured to the upper end of the whipstock proper and a locking ring at the upper end of the extension is provided with keys adapted to fit in slots formedin the drill rod knuckle joint. Thus, while being lowered or withdrawn from the well the whipstock is locked to the drill rods at the knuckle joint, the bit being housed during that time within the tubular extension of the whipstock. When the whipstock has been placed in the desired position in 'the hole, the look at the knuckle joint is released and the bit and drill rods pass downwardly throughthe locking ring and tubular extension For a better understanding of the invention,

reference, may be had to the accompanying dr n i h ch I rin a n a Figure 2 is, a verticalfsectional elevation of Figure 1 is a. sideelevation of the whipstock showing the tubular extension and the locking the device shown. in, Figure 1;

Figure 3 is a vertical elevation of the lower portion of the drill rods showing the bit and the knuckle joint on a somewhat larger scale than Figures 1 and 2, while Figure 4 is a side elevation partly in section showing the three parts of the knuckle joint on a still larger scale.

Referring to Figures 1 and 2 of the drawing, a whipstock Ill preferably of brass or other nonmagnetic metal and having a lower tapered portion I! and an upper hollow or tubular portion 10 I4, has secured at its upper end a tubular extension or nipple IS. A locking ringpr sub I8 is secured as by a threaded connection to the upper end of the extension l6 and is provided with a chamber adapted to house a knuckle 15 joint on the drill rods as will be explained hereinafter. A pair of oppositely disposed keys 22 project into the chamber 20.

With reference to Figures 3 and 4, the bottom section of drill pipe or rod 24 having a collar 26 go is adapted to be secured by a suitable threaded connection, not shown, to a sub or nipple 28 which in turn has a threaded connection with the upper end of a socket member 30. The member 30,shown in greater detail in Figure 4, comprises onesction' of a knuckle joint 32, the three parts of which are shown detached in that figure. The upper part 30 of the knuckle joint has an internally threaded portion 34 for connection with the sub 28 and a lowerinternally threaded :0

portion 36 into which the threaded end of a bushing 38 is adapted to be connected. Between the two ends 34 and 36 of the socket member 30 is a chamber 40 having a concave surface 42 adapted to form a bearing for the upper ball 85 shaped end 44 of a tubular member 46.

The ball shaped head 44 is provided with-a plurality of grooves or slots 48 and the chamber 40 is provided with a corresponding number of pro jections or keys 50. The slots 48 are slightly wider than the keys 50 and when the three parts of the knuckle joint are assembled the keys 50 will fit loosely within the slots 48. Thus, through the provision of the keys and slots any rotary motion of the socket member 30 will be transmitted to the tubular member 46 while at the same time the latter member may be moved angularly to a slight extent with respect to the socket member 30. When assembled, the bush- 50 mg will, of course, be threaded into the lower end 36 of the socket member 30 and tightened to such an extent that there will be no longi tudinal play between the members 30 and 46. The upper inner edge 52' of the bushing" is beveled to engage the lower spherical surface of the ball head 44. I

The lower end of the member l6 is threaded at El ior connection with the upper end of a tubular extension 58 and to the lower end of this extension the drill bit 58 is secured by any suitable connection. a

Two opposite external sides of the socket member 30 are cut away or tapered as at 58 and at the lower end of each cut away portion a J- shaped slot 60 is provided in the outer surface of the socket member. As will be noted with reference to Figures 3 and 4, the slot 60 has a horizontal portion 62 and a depending or vertical portion 64. An annular shoulder 66 is provided on the socket member 30, this shoulder being adapted to engage a similarly shaped shoulder 68 in the locking ring H3 at the upper end of the whipstock.

In operation, the lower end of the drill stem is made up or assembled as shown in Figure 3 and the whipstock as shown in Figures 1 and 2 is made up around the drill stem, the upper end of the locking ring I8 encircling the collar 26 or the sub 28. On pulling the drill stem upwardly, the keys 22 in the chamber will slide along the inclined surfaces 58 of the socket member 30 until they enter the slots 60, and on turning the drill stem a slight amount in a right hand direction, the keys 22 will move along the horizontal portions 62 of the slots 60 and will then drop into the depending portions 64 of the slots. The whipstock will then remain locked in that position and may be lowered into the hole on the drill rods in the usual manner. With the knuckle joint thus held securely in position in the locking ring l8, the extension 56 and the drill bit 58 will be housed within the nipple I6 and the tubular portion ll of the whipstock, the teeth of the bit being approximately at the level indicated by the dotted line 10.

If desired an inclinometer or other surveying instrument can be lowered through the drill pipe and out through the bit where it will lie against the inclined face of the whipstock to record or indicate the position of the latter.- The whipstock being formed of brass or other nonmagnetic metal will not interfere with a compass or other magnetic device incorporated in the surveying instrument.

Since the member 46 and the other parts of the knuckle joint as well as the extension 56 are hollow, drilling fluid can be circulated downwardly through the drill pipe and out through the whipstock to clean the hole ahead of the whipstock as the latter is being lowered. The tight joint obtained by the shoulders 66 and 68 will prevent the drilling fluid from passing upwardly out of the whipstock.

When the whipstock has reached the desired position in the hole the drill rods will be lowered slightly and then rotated in a left hand direction until the projections or keys 22 have become disengaged from the slots 60, whereupon the drill rods will again be lowered until the bit 58 engages the tapered portion I! of the whipstock after which the bit will be rotated in the usual manner to drill the hole. The angular movement which is provided by the knuckle joint will allowv for an additional three or four degrees of deviation.

When it is desired to remove the whipstock from the hole the drill rods are raised until the I keys 21 engage and are locked in the slots 60' after which the whipstock can be pulled to the surface. It will thus be seen that a device has been provided which will allow for a greater than usual deviation of the drilling bit and by means 01 which the whipstock can be easily removed from the hole after it has served its purpose.

Obviously many modifications and variations of the invention may be made without departing from the spirit and scope thereof, and therefore only such limitations should be imposed as are indicated by the appended claims.

I claim:

1. In a device for controlling the direction of a drill hole, a whipstock having a tapered portion and a locking ring secured to the upper end thereof, a string of drill pipe, a bit secured to the lower end of said drill pipe, a ball and socket joint disposed in said string of drill pipe above said bit to provide for angular movement of said bit with respect to said drill string, and means on said drill stem adapted to engage said locking ring for rigidly supporting said whipstock while the latter is being lowered or raised in said drill hole.

2. In a device for controlling the direction of a drill hole, a whipstock having a tapered portion and a locking ring secured to the upper end thereof, a string of drill pipe comprising a plurality of pipe sections, a bit secured to the end of said drill pipe, 2. knuckle joint disposed in said string of drill pipe above the lowermost pipe sec tion to provide for angular movement of said bit and pipe section with respect to said drill string, and means associated with said knuckle joint and adapted to be engaged by said locking ring for supporting said whipstock from said drill string while being lowered or raised in said drill hole.

3. In combination with a whipstock for controlling the direction of a drill hole, a drill stem, a bit secured to said drill stem, a flexible joint in said drill stem near said bit to provide for slight angular movement of said bit with respect to said drill stem, 2:. locking ring secured to the upper end of said whipstock and means associated with said flexible joint for cooperating with said locking ring to support said whipstock on said drill stem while being lowered or raised in said hole, said means being releasable when said whipstock has been placed in position in the hole to permit said bit to pass downwardly over said whipstock.

4. In combination with a whipstock for controlling the direction or a drill hole, said whipstock having a lower tapered portion and an upper tubular portion, a locking ring secured to the upper end of said tubular portion, a drill stem comprising a plurality of pipe sections, a bit secured to said drill stem, a flexible joint in said drill stem between the lowermost section of the drill pipe and the remainder of said stem, releasable means associated with said flexible joint and adapted to be engaged by said locking ring to support said whipstock on said drill stem with said lowermost section of drill pipe housed within the tubular portion of said whipstock while said whipstock is being lowered or raised.

5.. In a device for controlling the direction of a drill hole, a whipstock having a tapered portion and a locking ring secured to the upper end thereof, a drill stem, a bit secured to the end of said drill stem, a locking member on said drill stem disposed above said bit, said locking member being provided with a plurality of slots in its exterior surface, and a plurality of keys projecting from the inner. surface of said locking ring and adapted to engage said slots in a bayonet connection to lock said whipstock to said drill stem while said whipstock is being lowered or raised in said drill hole.

6. In a device for controlling the direction of a drill hole, a whipstock having a. tapered portion and a locking ring secured to the upper end thereof, a string of drill pipe, a bit secured to the lower end of said drill pipe, a ball and socket Joint disposed in said string of drill pipe above said bit to provide for angular movement of said bit with respect to said drill string, and locking means on said drill stem adapted to engage said locking ring for rigidly supporting said whipstock while the latter is being lowered or raised in said drill hole, said means comprising a key projecting from said locking ring and adapted to cooperate with a slot provided in" said locking means.

ODIE TROTIER. 

